Mechanical arm hole-making positioning system and method based on laser alignment and vision measurementTechnical Field
The invention relates to the field of intelligent equipment and automatic assembly, in particular to a mechanical arm hole-making positioning system and method based on laser alignment and vision measurement.
Background
at present, the satellite structure mostly adopts the structure of an aluminum honeycomb structural plate and a carbon fiber skin honeycomb bearing cylinder. As satellite layout increasingly adopts high-precision satellite-borne instruments mounted on the structural side plates, higher requirements are put forward on the repeated mounting precision of the structural side plates.
As the prefabricated hole precision deviation of the composite material structural member is large, in order to ensure the assembly quality, the satellite structure assembly screw hole generally adopts a drill-matching process, namely, the through hole of the structural member is matched as a threaded hole of a connected member. The bottom hole is drilled by a pistol drill, and the following problems exist:
1. the manual drilling and tapping parameters and the hole depth are difficult to control quantitatively, and the quality problem is easy to occur. The satellite structure is mostly a honeycomb panel, a carbon fiber bearing cylinder and other composite material structures, and has higher requirements on drilling and tapping. In manual operation, quality problems are easily caused because the rotating speed, feeding and the like cannot be accurately controlled.
2. the accuracy discreteness of the threaded hole is large, and the verticality is not easy to guarantee. When the drill is matched, manual punching is generally carried out by using a drill bushing for guiding, but in actual operation, the perpendicularity of a screw hole cannot be accurately ensured due to poor fixation of the drill bushing.
3. the labor intensity is high and the operation efficiency is low. When the satellite is provided with holes, operators need to be in positions of ascending, bending, arm extending and the like, the labor intensity is high, and the collision and damage to the satellite are easy to cause. Sometimes, in order to ensure the verticality, people are required to cooperate with the observation drill to observe the feeding verticality, and the efficiency is low.
The invention with application number 201811218616.0 provides drilling equipment and a drilling system, which relate to the technical field of drilling processing, and the drilling equipment comprises: the drilling device comprises a first transmission device, a positioning device and a drilling device; the plate body comprises a side edge, a first end part and a second end part, wherein the first end part and the second end part are arranged around the side edge; the positioning device comprises a first positioning mechanism and a second positioning mechanism which are respectively arranged corresponding to the first end part and the second end part of the plate body, the first transmission device can drive the plate body to move to a preset first end positioning position along a first movement direction and can drive the plate body to move to a preset second end positioning position along a second movement direction, the first positioning mechanism is configured to position the first end part at the preset first end positioning position, and the second positioning mechanism is configured to position the second end part at the preset second end positioning position; and after the plate body is positioned, the drilling device performs drilling processing on the positioned end of the plate body. This application has reduced the drilling position positioning deviation that the plate body leads to because of warping, has improved the precision of drilling location. But the drilling method provided by the scheme has the advantages of larger accuracy discreteness of the threaded hole and difficulty in guaranteeing the verticality.
Disclosure of Invention
Aiming at the defects in the prior art, the invention aims to provide a mechanical arm hole-making positioning system and method based on laser alignment and vision measurement.
The invention provides a mechanical arm hole-making positioning system based on laser alignment and vision measurement, which comprises a laser ranging sensor, an intelligent camera, a hole-making actuator platform, a mechanical arm hole-making control system and a mechanical arm body control system, wherein the mechanical arm hole-making positioning system comprises a laser ranging sensor, an intelligent camera, a hole-making actuator platform, a mechanical arm hole-making control system and a mechanical arm body control system, wherein the mechanical:
The laser ranging sensor and the intelligent camera are arranged on the drilling actuator platform;
the laser ranging sensor and the intelligent camera respectively acquire ranging data and image data and send the ranging data and the image data to the mechanical arm hole making control system;
the mechanical arm hole making control system is used for processing data measured by the laser range finder and the intelligent camera;
the mechanical arm body control system is used for controlling the motion of the mechanical arm.
preferably, the laser ranging sensor comprises a safety monitoring laser ranging sensor and a normal alignment laser ranging sensor, wherein:
the laser emitting direction of the safety monitoring laser ranging sensor is parallel to the extending direction of the electric spindle of the mechanical arm;
The normal alignment laser ranging sensor is used for measuring the positions of the electric spindle of the mechanical arm and a workpiece product and providing a normal vector of a workpiece plane added by the mechanical arm.
preferably, the smart camera comprises a wide-angle lens smart camera and a telephoto lens smart camera, wherein:
The wide-angle lens intelligent camera is used for scanning the planar stepped hole of the workpiece and determining the rough positioning of the hole position;
the telephoto lens intelligent camera is used for determining a hole making position and judging a hole making size.
preferably, the wide-angle lens intelligent camera and the telephoto lens intelligent camera each include an imaging system and an image processing system therein.
Preferably, the mechanical arm hole making control system comprises a data acquisition interface and a data processing system, wherein;
the data acquisition interface adopts a bus communication mode to acquire position and distance information transmitted by the laser ranging sensor, the intelligent camera and the mechanical arm body control system, and the data processing system performs data processing and resolving to obtain hole making position information.
Preferably, the mechanical arm body control system receives an instruction sent by the mechanical arm hole making control system, and the mechanical arm positions the hole making position according to the instruction.
the invention also provides a mechanical arm hole-making positioning method based on laser alignment and vision measurement, which comprises the following steps:
and (3) coordinate system confirmation: selecting a plurality of points of a workpiece by a manual guiding mechanical arm for guiding and teaching, and confirming a coordinate system of the workpiece;
and a mechanical arm posture adjusting step: the laser ranging sensor adjusts the posture of the mechanical arm;
An intelligent camera positioning step: the intelligent camera positions the workpiece;
A hole making step: according to the accurate position and size of the stepped hole of the machined part and the normal direction of the working surface of the corrected stepped hole, the mechanical arm automatically calls tools to drill the regions to be drilled of the frame structure of the machined part one by one.
Preferably, the robot arm posture adjusting step includes:
Coarse adjustment of the posture of the mechanical arm: the mechanical arm selects a plurality of points around each point of the plurality of points guided manually as 1 group, the normal alignment laser ranging sensor is adopted for measurement, the data of each group of the plurality of points are recorded, the average value is taken as the calculation basis, the workpiece coordinate system is calculated according to the information of the plurality of groups of point positions, and the posture of the mechanical arm is roughly adjusted;
Fine adjustment of the posture of the mechanical arm: and (3) according to the workpiece coordinate system determined in the step of roughly adjusting the posture of the mechanical arm, carrying the normal alignment laser ranging sensor by the mechanical arm again to measure the more accurate workpiece coordinate system, finely adjusting the posture of the mechanical arm, and finding an accurate normal direction of a processing plane when an included angle gamma between the axial direction of the electric spindle tool of the mechanical arm and the processing plane is less than or equal to 0.5 DEG to realize the accurate calibration of the posture of the mechanical arm.
Preferably, the smart camera positioning step comprises:
Step of coarse positioning of step hole site scanning of the wide-angle lens intelligent camera: after the normal alignment and the correction of the mechanical arm are finished, the mechanical arm carries a wide-angle lens intelligent camera to scan the plane of the workpiece, and after data processing and resolving of a mechanical arm hole making control system, rough position and quantity information of a stepped hole of the plane of the workpiece are drawn;
The method comprises the following steps of (1) accurately positioning the circle center of a stepped hole of a telephoto lens intelligent camera: the arm carries tele lens intelligence camera according to normal direction and the shoulder hole approximate position after correcting, shoots every shoulder hole in proper order, and arm system hole control system carries out data processing and solves the back, realizes the accurate position of shoulder hole centre of a circle.
Preferably, the pixels of the wide-angle lens smart camera are 200 ten thousand pixels and the pixels of the telephoto lens smart camera are 500 ten thousand pixels.
Compared with the prior art, the invention has the following beneficial effects:
1. According to the invention, the distance between the drilling actuator platform and the workpiece product is monitored in real time through the safety monitoring laser ranging sensor, so that the product safety is protected to the greatest extent; measuring the positions of the electric main shaft of the mechanical arm and the workpiece by a normal alignment laser ranging sensor, accurately searching a normal vector of a plane of a machined part, and ensuring the perpendicularity of hole making; the step hole site scanning coarse positioning is realized through a wide-angle lens intelligent camera, the circle center of the step hole is accurately positioned through a long-focus lens intelligent camera, and the hole making position precision is ensured; and a high-precision servo drive drilling actuator platform is adopted, so that the depth precision of drilling is ensured.
2. The invention links 2 laser ranging sensors, 2 intelligent cameras, a hole making actuator platform and a mechanical arm body control system through software and hardware of the mechanical arm hole making control system, realizes the calibration of the posture of the mechanical arm by adopting a laser normal alignment control algorithm, and realizes the accurate positioning of the hole making position of the mechanical arm by adopting a vision precision measurement calibration method, thereby guiding the mechanical arm to make holes accurately, forming a precise self-feedback system, and having wide application prospect in the fields of aviation, aerospace and the like.
Drawings
other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:
FIG. 1 is a schematic block diagram of a robotic arm hole-making positioning system based on laser alignment and vision measurement according to the present invention;
FIG. 2 is a schematic diagram of a robot arm hole-making application scenario based on laser alignment and vision measurement according to the present invention;
FIG. 3 is a flowchart of a mechanical arm hole-making positioning method based on laser alignment and vision measurement.
In the figure:
mechanical arm hole-making positioning system 1
Drilling actuator platform 11
Laser ranging sensor 12
safety monitoring laser ranging sensor 121
Normal alignment laser ranging sensor 122
Intelligent camera 13
Wide-angle lens intelligent camera 131
First imaging System 1311
First image processing system 1312
telephoto lens smart camera 132
Second imaging system 1321
second image processing system 1322
Mechanical arm hole making control system 14
data acquisition interface 141
data processing system 142
the robot arm body control system 15.
Work piece 2
Machined part plane stepped hole 21
Drilling location 22
processed body frame structure 23
work piece product 24
A hole making area 25
Detailed Description
The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that it would be obvious to those skilled in the art that various changes and modifications can be made without departing from the spirit of the invention. All falling within the scope of the present invention.
As shown in fig. 1, the present invention provides a mechanical arm drilling positioning system 1 based on laser alignment and vision measurement, comprising: 2 laser ranging sensors 12; 2 smart cameras 13; a hole making actuator platform 11; a robotic arm hole making control system 14; the robot arm body control system 15. 2 laser ranging sensors 12, which are respectively a safety monitoring laser ranging sensor 121 and a normal alignment laser ranging sensor 122. The laser emitting direction of the safety monitoring laser ranging sensor 121 is parallel to the extending direction of the electric spindle of the mechanical arm, the distance between the drilling actuator platform 11 and the machined part product 24 is monitored in real time, and the product safety is protected to the greatest extent; the normal alignment laser ranging sensor 122 is used for measuring the positions of the electric spindle of the mechanical arm and the workpiece product 24, and provides a normal vector of a workpiece plane added by the mechanical arm by measuring three-point positions, so that a spindle cutter is perpendicular to the plane for hole making, and the verticality precision of the hole making is ensured. 2 smart cameras 13, a wide-angle lens smart camera 131 and a telephoto lens smart camera 132, respectively. The wide-angle lens intelligent camera 131 is responsible for scanning the added workpiece plane stepped hole 21 and determining the rough positioning of the hole position, and a powerful professional machine vision system is built in the camera and comprises a first imaging system 1311 and a first image processing system 1312; the telephoto lens smart camera 132 is responsible for determining the precise location 22 of the hole and determining the size of the hole, and a powerful professional machine vision system is built in the camera, including a second imaging system 1321 and a second image processing system 1322. Drilling executor platform 11 for fixed laser rangefinder sensor and intelligent camera adopt high accuracy servo drive, guarantee the degree of depth precision in drilling, and above-mentioned 2 laser rangefinder sensors 12 and 2 intelligent cameras 13 are all installed on executor platform 11. The mechanical arm drilling control system 14 is used for processing data measured by the laser range finder and the intelligent camera and comprises a data acquisition interface 141 and a data processing system 142. The data acquisition interface 141 acquires information such as positions and distances transmitted by the 2 laser ranging sensors 12, the 2 intelligent cameras 13 and the mechanical arm body control system 15 in a bus communication mode, the data processing system 142 processes and resolves the information to obtain hole making position information, and the mechanical arm hole making control system 14 sends an instruction to the mechanical arm body control system 15 to enable the mechanical arm to accurately position the hole making position according to the information. And the mechanical arm body control system 15 is used for controlling the high-precision and high-reliability movement of the mechanical arm.
The invention also provides a mechanical arm hole-making positioning method based on laser alignment and vision measurement, as shown in fig. 3, the implementation steps are as follows:
Roughly measuring a workpiece coordinate system: the manual guiding mechanical arm selects three points on the workpiece product 24 for guiding and teaching, and preliminarily confirms a workpiece coordinate system;
coarse adjustment of the posture of the mechanical arm: switching to a functional program for calibrating a workpiece coordinate system by a mechanical arm, selecting 3 points by the mechanical arm around each of the manually guided 3 points as 1 group, measuring by using a normal alignment laser ranging sensor, recording data of the three points in each group, calculating an average value of the data, and performing alarm processing on the points with abnormal and sudden data changes as a calculation basis; calculating a workpiece coordinate system according to the 3 groups of point position information, and coarsely adjusting the posture of the mechanical arm;
Fine adjustment of the posture of the mechanical arm: according to the workpiece coordinate system determined in the step II, the mechanical arm carries the normal alignment laser ranging sensor again to measure the workpiece coordinate system more accurately, the posture of the mechanical arm is finely adjusted, and when the included angle gamma between the axial direction of the electric main shaft tool of the mechanical arm and the processing plane is less than or equal to 0.5 degrees, the accurate normal direction of the processing plane is found, so that the accurate calibration of the posture of the mechanical arm is realized;
Step of coarse positioning of step hole site scanning of the wide-angle lens intelligent camera: after the normal alignment and the correction of the mechanical arm are finished, the mechanical arm carries 200 ten thousand pixels of a wide-angle lens intelligent camera to scan the plane of the workpiece, and after data processing and resolving are carried out by a mechanical arm hole making control system 14, approximate position and numerical information of a stepped hole 21 of the plane of the workpiece are drawn;
the method comprises the following steps of (1) accurately positioning the circle center of a stepped hole of a telephoto lens intelligent camera: the mechanical arm carries 500 ten thousand pixels of the telephoto lens intelligent camera according to the corrected normal direction and the approximate position of the stepped hole 21, each stepped hole is photographed in sequence, and after data processing and resolving are carried out by a mechanical arm hole making control system, the position 22 of the center of the stepped hole is realized;
a hole making step: and according to the accurate position and size of the stepped hole and the normal direction of the working surface of the corrected stepped hole, automatically calling a corresponding tool by a mechanical arm, and drilling the to-be-drilled area 25 of the processing body frame structure 23 one by one.
The foregoing description of specific embodiments of the present invention has been presented. It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes or modifications may be made by one skilled in the art within the scope of the appended claims without departing from the spirit of the invention. The embodiments and features of the embodiments of the present application may be combined with each other arbitrarily without conflict.